A control plane message of a Long Term Evolution (LTE) system is used to ensure normal operation of the system, normal establishment and disengagement of a service connection, and the like. Therefore, reliability of the control plane message is extremely important in the LTE system. For example, in an architecture of an LTE evolved packet core (EPC), after a mobility management entity (MME) receives a downlink data communication message sent by a serving gateway (SGW), the MME needs to send a paging message to all evolved NodeBs (eNB) in a tracking area list (TA List) in which a user is located, so that the eNB forwards the paging message to a user equipment (UE). After receiving the paging message, the UE can initiate a radio resource control (RRC) connection, to receive data. A paging packet is sent using S1 signaling between the MME and the eNB, and the S1 signaling and X2 signaling that is between the eNBs are transmitted based on the Stream Control Transmission Protocol (SCTP).
In a scenario of high load, because a quantity of SCTP signaling is relatively large or signaling traffic is relatively large, network congestion occurs in the system. Retransmission of excessive lost packets may cause an avalanche effect. In a severe case, link breaking is caused, and consequently other services can hardly be processed. Congestion control and congestion avoidance need to be properly performed, to avoid an MME/eNB exception caused by SCTP congestion.